LaTeX provides commands for making overlines or underlines, or putting braces over or under some material.
\underline{text}
¶Underline text. Works inside math mode, and outside.
The line is always completely below the text, taking account of
descenders, so in \(\underline{y}\)
the line is lower than in
\(\underline{x}\)
. This command is fragile (see \protect
).
Note that the package ulem
does text mode underlining and allows
line breaking as well as a number of other features. See the
documentation on CTAN. See also \hrulefill
& \dotfill
for
producing a line, for such things as a signature.
\overline{text}
¶Put a horizontal line over text. Works inside math mode, and
outside. For example, \overline{x+y}
.
Note that this differs from the command \bar
(see Math accents).
\underbrace{math}
¶Put a brace under math. For example, this
(1-\underbrace{1/2)+(1/2}-1/3)
emphasizes the telescoping part.
Attach text to the brace by using the subscript command, _
, or
superscript, ^
, as here.
\begin{displaymath} 1+1/2+\underbrace{1/3+1/4}_{>1/2}+ \underbrace{1/5+1/6+1/7+1/8}_{>1/2}+\cdots \end{displaymath}
The superscript appears on top of the expression, and so can look unconnected to the underbrace.
\overbrace{math}
¶Put a brace over math, as with
\overbrace{x+x+\cdots+x}^{\mbox{\(k\) times}}
. See also
\underbrace
.
The package mathtools
adds an over- and underbrace, as well as
some improvements on the braces. See the documentation on CTAN.